| Autor: |
Patra BC; School of Applied and Interdisciplinary Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India., Datta S; School of Applied and Interdisciplinary Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India., Bhattacharya S; Department of Organic Chemistry, Indian Institute of Science, Bangalore 560012, India.; School of Applied and Interdisciplinary Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India.; Department of Chemistry, Indian Institute of Science Education and Research, Tirupati 517619, India. |
| Jazyk: |
angličtina |
| Zdroj: |
ACS applied materials & interfaces [ACS Appl Mater Interfaces] 2024 Feb 14; Vol. 16 (6), pp. 7650-7659. Date of Electronic Publication: 2024 Feb 05. |
| DOI: |
10.1021/acsami.3c15339 |
| Abstrakt: |
Luminescent covalent organic frameworks (LCOFs) have been employed as platforms for sensing analytes. Judicial incorporation of appropriate functional units inside the framework leads to the different electronic states in the presence of external stimuli, e.g., temperature, pH, etc. We report herein a new COF ( TPEPy ) as a solid-state acid sensor specific for the highly acidic environments that range from pH ∼0.5 to ∼3.0. This COF shows a protonation-induced reversible color change from bright yellow to deep red upon decreasing the pH from 3 to 0.5 and vice versa. No visual color change was, however, observed above pH 3.0. Photoluminescence (PL) studies show that the intrinsic emission peak of the TPEPy COF at 530 nm is shifted to 420 nm owing to the N-protonation of the imine nitrogen of COF within this pH range. Extensive studies demonstrate that the protonation behavior of the COF is counterion dependent. This was revealed when different acids, e.g., HCl, HNO 3 , HBr, and HI, were employed. The intensity of the proton-induced emission peak at 420 nm depends significantly upon the counterions with the order of HCl > HNO 3 > HBr > HI. These anions interact with the protonated TPEPy COF by cation-anion and H-bonding interactions. Further, the pristine COF showed near white light emission at a particular pH of 2.5 (CIE coordinates 0.27, 0.32). From the PL spectrophotometric titrations, the deprotonation p K a was experimentally found to be 1.8 ± 0.02 for the TPEPy COF. The sensor reported herein is reversible, reusable, and regenerable and is useful for assessing pH fluctuations within a strongly acidic range via digital signaling. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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